textproduct: Rapid City

KEY MESSAGES

- Widespread precipitation tapers off this afternoon and evening.

- Cold temperatures continue with a freeze warning in effect Tuesday morning.

- Gradual warmup mid-week with precipitation chances returning towards the weekend.

DISCUSSION

(This Evening Through Monday) Issued at 128 PM MDT Mon May 18 2026

Current Water Vapor and upper air models show troughing just east of the Rockies running through the northern and central plains, with upper ridges over the New England region and off the west coast. 19Z surface analysis depicts a surface low to our east over MN, surface high over central MT. Radar shows widespread precipitation across the forecast area, with some of the higher elevations receiving light accumulations of snow today. Winds are currently breezy out of the northwest to north, with temperatures in the 30s to low 40s.

Precipitation will taper off from west to east late afternoon through the evening, as trough slides eastward today. Cool temperatures continue tonight as clouds clear up and light northwest winds continue. Much of the area is expected to reach near or below freezing overnight. HREF probability for temps to reach at or below freezing sit at 80-100% for areas from the Black Hills and west. Further east will be a bit trickier as cloud cover will linger into tonight as the trough slowly shifts eastward. A Freeze warning has been issued for most of our plains areas, with a frost advisory in effect for part of south-central SD for Tuesday morning.

Brief and weak ridge sets over the region mid-week, resulting in drier conditions and a warming trend towards near seasonable. Another wave rides southeast from western Canada towards the northern plains later in the week, increasing chances for precipitation late Thursday into Friday. Shortwave ridging moves over the weekend, bringing warmer temps back in as well. By Sunday/Monday the region should see highs climb back into the 80s to low 90s.

AVIATION

(For the 18Z TAFS Through 18Z Tuesday) Issued At 1114 AM MDT Mon May 18 2026

Precipitation and low clouds are crossing the region with MVFR/LIFR conditions. Local LIFR conditions may occur in/near the Black Hills due to snow. Conditions will slowly improve late this afternoon and evening.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Freeze Warning from midnight tonight to 9 AM MDT Tuesday for SDZ001-002-012>014-025>027-030>032-041>044-072>078. Frost Advisory from 1 AM to 10 AM CDT Tuesday for SDZ046-047. WY...Freeze Warning from midnight tonight to 9 AM MDT Tuesday for WYZ054>056-058>060.